Poppet-valve mechanism for power actuators and the like



Aug. 7, 1923. 1,679,762

(:45. BRAGG 'r AL POPPET VALVE MECHANISM FOR POWER ACTUATORS ANDVTHELIKE- Original Filed Oct. 20, 1925 2 s t -s t l avwento'zs C. S. BRAGGET AL POPPET VALVE MECHANISM FOR POWER ACTUATORS AND THE LIKE 2Sheets-Sheet Original Filed Oct. 20; 1925 W Wall/A7 72 I a I,

A MW Q Patented Aug. 7, 1928.

UNITED STATES PATENT OFFICE.

CALEB S. BRAGG, OF PALM BEACH, FLORIDA, AND VICTOR W. KLIESRATH, 01'PORT "WASHINGTON, NEW YORK, ASSIGNORS TO RRAGG-KLIESRATH CORPORATION, OFLONG ISLAND CITY, NEW YORK, A CORPORATION OF NEW YORK. I I

POPPET-VIALVE MECHANISM FOR POWER ACTUATORS AND TEE LIKE;

Application filed October 20, 1925, Serial No. 63,697. Renewed June 22,1827.

Our invention consists in the noval features hereinafter described,reference being had to the accompanying drawings, which illustrate oneembodiment of the same, selected by us for purposes of illustration, andthe said invention is fully disclosed in the following description andclaims.

Our present invention consists in an improved power actuator of the typeshown in our former application for Letters Patent of the United Statesfiled December 22, 1923, Serial No. 682,346, said actuator comprising acylinder, closed at both ends, a double acting piston in the cylinder,means for subjecting the piston to differential pressures on itsopposite faces, preferably by providing the cylinder with a connectionleading to a suction device, which is usually and conveniently theintake manifold of an internal combustion engine, and providing thecylinder also with means for admitting higher pressure fluid, asatmospheric ,air, the differential pressures being controlled byreversing valve mechanism, preferably located in the hub of the pistonand operated by a foot lever, or other operator operated part. Theseactuators are especially adapted to the operation of brake mechanism orother devices to be operated on an automotive vehicle propelled by theinternal combustion engine and operating on land, in or upon;

water, or in the air. Our present invention consists in certain novelfeatures embodied in the actuator, by means of which the reversing valvemechanism is connected directly, with the atmosphere in such manner asto avoid the use of by-passes, whereby the piston is guided in itsmovements more efiiciently, and positively preventing from cocking or inother words, getting out of coaxial relation with the cylinder, andwhereby the apparatus within the c linder is protected from dirt andwater. ur invention also comprises certain other novel featureshereinafter described and fully pointed out in .the claims.

Referring to the accompanying drawings, which illustrate one embodimentof our.in-' vention, selected by us for purposes of illustration,

Fig. I, is a sectional view of one form of our improved actuatorembodying our present invention, and illustratingin connectiontherewith, an operator, operated part for controlling the reversingvalve mechanism, which is shown in its normal retracted or off positionin this figure.

Fig. 2 is a similar view showing the position of the apparatus after thepiston has .been actuated and the valve mechanism has been operated toeffect the return of the piston to normal position.

In the accompanying drawings, 1, represents the cylinder of our improvedactuator provided with heads, 2, each of which has a sleeve portion, 2,having an aperture therethrough for guiding a piston rod, and a stuflingbox, indicated at 2*, for the same.

.3, represents the double acting piston provided with oppositelydisposed gaskets, 4,4, the said piston having a hub, 10, in which thereversing valve mechanism, hereinafter described, is located, and beingprovided at each end with a hollow piston rod, indicated 'at 5, 5*,respectively, rigidly secured to the hub in any usual or desired manner,and extending through the guiding apertures in the sleeves, 2*, of thehead. Each of the stuffing boxes, 2 in the heads is provided with aflanged packing sleeve, indicated at 6, 6, respectively, and held in'lace by,a follower, 6, said packing sleeves eing preferably formed ofmolded rubber and adapted to make air tight joints between the ends ofthe cylinder and the adjacent piston rods, while permitting the pistonrods to move therethrough. By providing the piston with two piston rods,in the manner shown and described, the piston will be guided in itsmovements by the engagement of each pis' ton rod with its bearingaperture in the adjacent head of the cylinder,thus preventing cocking ofthe piston, and insuring the ac-' curate movement of' the same withinthe The piston hub, 10, is preferably provided I centrally thereof witha suction, or outlet valve seat, 14, While the chamber, 12, is pro videdwith the air inlet valve seat, 16, and

the suction valve seat, 15. 20 represents a valve actuating sleeve,which extends through the cylinder, the hollow piston rod, and the hub,10, of the piston, and is provided within each of the valve chambers,11-

and 12, with oppositely disposed air inlet and suction valves, coaxialwith respect to the sleeve, 20, and provided with central aperturesthrough which the sleeve passes, means being provided to make thiscentral aperture air tight, 'while permitting the sleeve to movelongitudinally through the valves. Within the valve chamber, 11, thevalve sleeve is provided with an inlet valve,

40, for engaging seat, 13, and a suction valve, 41, for engaging seat,14. Within the valve chamber, 12, the sleeve is provided with a suctionvalve, 42, engaging seat, 15,

' and an air inlet valve, 43, engaging seat, 16.

We prefer to make these valves of molded rubber, having their centralapertures so formed as to fit the exterior of the sleeve air tight,while permitting the valve sleeve to move longitudinally with respect tothe valite. The pair of valves in each chamber is provided with meansfor yieldingly pressing each valve in a direction toward its seat. Inthis instance we have illustrated the spring washers, 50, interposedbetween the valves, 40 and 41, and between the valves, 42 and 43, forelastically pressing them towards their seats, said spring washers asshown being of the kind shown in our former application for LettersPatent filed October 2, 1925, in which theyare specifically claimed. Thespecific construction of these spring washers has no bearing on ourpresent invention. The valve sleeve is pro-.

- .vided, also, with collars, one adjacent to each of said valves, forunseating it by longitudinal movement of the sleeve, said collars beingindicated respectively at 40 41*, 42, and 43. In practice, we prefer toprovide means for limiting the extent to which the valve actuatingsleeve, 20, may project into the cylinder which consists in thisinstance of a stop collar, 21, adjustably secured to the sleeve, in thisinstance being threaded thereon, and held in adjusted position by asetscrew, 21, the said sleeve being adapted to in shown, and the collarsfor actuating the valves are so located that'when the sleeve and pistonare-in this position, the suction -valves 41 and .42 will be held ofi oftheir respective seats, while the valves 40 and 43 will be seated, andthe collars, 40 and 43*, are located a little distance away from thecorresponding valves, so that the valve sleeve may be moved far enoughto permit the corresponding suction valve to seat fully before either ofthese collars will engage an air inlet valve. -The valve chamber, 11, isconnected with the cylinder on one face of the piston, by a port, orports, 34, and the valve chamber, 12, is similarly connected. with thecylinder on the other face of the piston, by a port, or ports, 35, andtherefore in the normal or off position of the piston, the cylinder willbe connected at both sides of the piston with the suction chamber, andwill therefore be immersed or submerged in vacuum. For convenientlyconnecting the suction chamber, 17, with the source of vacuum, the valvesleeve is provided, internally, with a plug or partition, 23, justbeyond the suction chamber, and with lateral openings, 24, communicatingdirectly with the suction chamber, the adjacent portion of the sleeve,20, extending outside of the cylinder, and being connected with asuction pipe, 62, leading to a source of suction. We convenientlyprovide the outer extremity of the sleeve, 20, with a fitting, 25,communicating with the interior of the sleeve, and the suction chamber,and provide means for connecting itwith the suction pipe, 62, a portionof. which at least is flexible tubing, so as to permit the longitudinalmovement of the sleeve, and the said fittingis also provided withperforated lugs, indicated at 25,

for conveniently connecting the valve actuating sleeve with an operatoroperated part. In order to facilitate an understanding of the operationof the device, we have shown a foot lever, 30, pivoted at 31, providedwith aretracting spring. 32, and connected by a link, 33, (shown brokenaway) with the lug, or lugs, 26. The suction pipe, 62. is preferablyconnected to the, intake manifold of the internal combustion engine,used for propelling the vehicle, on which the actuator is employed,- asthis forms a convenient source of suction.

Air is admitted to the air inlet controlled by the valve, '43, throughan aperture at the outer end of the hollow piston rod, 5. In thisinstance we have shown the piston rod, 5, provided at its outer end w tha cap, or fitting, 36, enclosing it, provided With an air inletaperture, 37,'and also provided with lugs, 38, for convenience ofattaching the pistonrod, 5, to the part to be actuated,

as the brake mechanism of an automotive Vehicle, by means of a llIlk,indicated at 39.

'As the valve actuating sleeve conveniently extends through the hollowpiston rod, for

a reason hereinafter explained, it is convenient to permit the air whichenters through the aperture,.37, to pass through the end of the sleeve.20, beyond'the partition, 7

23, which separates it from the suction portion of the sleeve, and topass through lateral apertures, 24*, in the sleeve,-into the spacebetween the sleeve and the hollow piston rod, 5, indicated at' 5,through which annular passage it passes to the valve chamber,

12, when the valve, 43, is opened. Atmos-- pheric air is admittedto thevalve chamber,

11, through the annular space, indicated at 5 between the hollow pistonrod, 5, and

valve, 40, controlling the admission of air to valve chamber, 11, isnever.;opened, ex-

.cept for the purpose of returning "the plston to normal position atwhiclitime'the valve sleeve has moved in the direction of the arrow in lig. 1, so as to remove the collar,

21, from the end face or shoulder, '22-, of thecylinder head, and thepiston rod, 5, will have been projected from the cylinder head so thatair may readily enter through the apertures, 28, at such times.

Means'are also provided for limiting the longitudinal movement of thevalve actuati g sleeve, 20, withrespect to the piston in bothdirections, so that after the sleeve has been moved in either directionbeyond the pointvnecessary to effect the operation of the valvemechanism, the piston itself can be operated directly by the operatoroperated device, as in case of failure of power, or where the operatordesiresto add his physical force ,to the power of the. actuator in theapplication ofbrakes or other devices.

In this instance the interior end of'the valve sleeve projects into arecess in the cap or fitting, 36, and is provided with a collar; 14,adapted to be broughtinto engagement with an interior collar, 45.secured to the hollow piston rod, 5, to l mit the movement of the.

valve in thedirection of the arrow}, Fig. 1, and its movement intheopposite direction may be limited, when the device is in use by theengagement of ,the endaof the sleeve with the end. of the collar, 36.This mech anism. however, forms no part of 0ur pres-' ent invention, andW111 not be further described or claimed herein.

The parts being in the positions hidic5 cated in Fig. 1, the suctionpipe, 62, being connected 'with the source of suction, as the intakemanifold (a check valve, not shown, being preferably employed in saidpipe to insure the maximum degree-of rarification with the cylinder,which is obtained in the manifold between operations of the actua tor)it willbe seen that, assuming the engine to be running, air will beexhausted from the cylinder on both sides of the piston, leaving itsubmerged in vacuum, ready for instant operation. To effect theoperation of the device in the arrangement shown, the foot lever, 30, isdepressed (r moved in the directionof the arrow,']?ig. 1, thereby mov-'ing the valve sleeve, 20, longitudinally in the and the movement of.the piston will continue so long as the movement of the valve sleevecontinues. \Vhen the operator stops the move ment of the brake pedal, aslight continued movement of the. piston' engages the air inlet valve,43-, with its seat, 16, and shuts off the source of-pressure, whereuponthemovement, of the piston ceases. The further movement of the,piston,forward, maybe obtained by the further forward movement of the valvesleeve, again opening the valve, 43. If it is desired to slightlyrelease and reapply the brakes, as in continuedbraking on long grades,or in traific, a slight release of pressure on the foot lever will causea slight movement of the valve sleeve, 20, in

a direction opposite that indicated by the arrow in Fig. 1, andwill-restore the valve mechanism to. the position indicated in Fig;

1, although the plston will be further advancedin the cylinder, therebypermitting an equalization ofpressures within the cylinder' on 013 ositefaces of the piston, and connecting oth ends of the c linder with thesuction means, permitting the load of the applied brake bands to movethe piston slightly rearwardly and relievethe brakes, which calf beinstantly reapplied by a forward movement of the pedal, effecting theclosing of valve, 42, and a slight opening-of the valve, 43. Whenit isdesired to return the parts to their normal position, the operator willrelease the foot lever completely, usually by removing his food fromit,and

permitting it to he retracted'by its retracting spring, as indicated inFig. 2'. This will effect a quick movement of the sleeve, 20, in thedirection of. the arrow in that figure,

closingthe valve, 41, opening the valve 12 further, .closing the valve,43, and opening the valve, 40, thereby admitting atmospheric airthroughthe annular passage between the piston rod, 5 and the sleeve tothe cylinder on the forward face of the piston, and continuingcommunication between the cylinder on the rear face of the piston andthe suction chamber, thus moving the'piston back ward in the directionof the arrow, Fig. 2, until it is arrested by the engagementof its hubwith the head of the cylinder, and thereby withdrawing the piston rod,5, into the sleeve, 2, of the piston head.- Just before the piston is soarrested, the stop collar, 21, on the valve actuating sleeve, 20,engages the end face, 22, of the adjacent cylinder head, arresting themovement of the valve head in the direction ofthe'arrow, Fig. 2,permitting the air inlet valve, 40, to seat, cutting off furtheradmission of higher pressure fluid, and slightly opening the valve, 41,thereby permitting equalization of pressures on both sides of thepiston, and establishing the communication between the c linder on bothsides of the piston, and t e suction chamber, and exhausting the higherressure fluid, i. e., atmospheric air intro uced for the return movementof the piston. The parts will then be in the position indicated in F1g.1, and ready for another operation.

It 'will be seen that. the stop collar, 21, closes the aperture at theend of the sleeve, 2, of the adjacent cylinder head, andthereby ineffect closes the air inlet aperture, 2%},-

when the parts are in normal or off position. This end of the cylinderwill be ordinarily particularly subject to dirt and water, and this isnormally prevented from entering the space between the hollow pistonrod, 5, and the valve actuating sleeve, 20, thus protecting the valvemechanism therefrom. The air inlet passage, 5", at the opposite end ofthe cylinder between the hollow piston rod, 5, and valve sleeve, 20,

is also protected from dirt and water by the enclosing cap, 36, on theend of the piston rod, and the inlet aperture, 37, therein, ispreferably located in a vertical face of the cap, as shown, to moreeffectually keep out moisture and foreign matter, although this 50 endof the apparatus is ordinarily not in a position to receive so much ofthe splash when the device is installed in an automobile, as is theopposite end of the apparatus.

It will be seen that atmospheric air may be directly admitted from.either end of the cylinder, to the adjacent valve chamber when required,through the annular passages between the hollowpiston rods and thecoaxial valve actuating sleeve, without theuse of by-passes in the hubfrom one side of the piston to the other, which would otherwise berequired if the air was admitted at one end only of the cylinder. Theseair inlet passages are kept perfectlytight by means of the valves, 4.0,and 43, and extraneous packing is therefore unnecessary. The provisionof the two piston rods extending in opposite.directons through the headof the cylnder, also prevents any-tendency of the piston to cock ortwist in the cylinder, and renders the operation of the piston true anduniform at all times, and the construction of said hollow piston rodsbeing provided with means for conducting air under atmospheric pressureto the reversing valve mech anism, one of said piston rods being constructed so as to be withdrawn within the bearing aperture of thecylinder head through which it passes, when the piston is in offposition, a hollow valve actuating member extending through said hollowpistonrod and operatively connected with the reversing valve mechanismfor actuating the through the guiding same, means for connecting saidhollow valve actuating member with a source of suction, and a partcarried by said hollow valve actuating part for engaging the adjacentcylinder head when the piston is in ofi osition, to

limit the return movement of sai valve aclUO tuating part, and to closethe outer end of the bearing aperture in the cylinder head, and preventaccess'of water and dirt to the hollow piston rod engaging the saidbearing aperture.

2. A power actuator comprising among its members a cylinder having itsopposite ends closed by heads provided with bearing apertures, a doubleacting piston in said cylinder, reversing valve mechanism includingnormally closed air inlet valves each constructed to admit air on oneside of thepiston when in open position, and a pair of suction valveseach constructed to connect the cylinder on one side of the piston witha source of suction when in open position, a hollow piston rod extendingfrom opposite sides of said piston in opposite. directions, each havinga sliding engagement in the bearing aperture of one of said cylinderheads, means for admitting atmospheric air through each of said hollowpiston rods to-one of said air inlet valves, and a longitudinallymovable valve actuating sleeve extending through at least one of saidhollow piston rods 0 eratively connected with said suction and airvalves, and with means for connecting the control of said suctionvalves, means for connecting one of said hollgw piston rods with a partto be operated, and means ,for ,connecting said valve actuating sleevewith an operator operated part.

3. A power actuator comprising among its members a cylinder having itsopposite endsclosed by heads provided with bearing apertures, a doubleacting piston in said cylinder, reversing valve mechanism, includingnormally closed air inlet valves each constructed to admit air on oneside of the piston when in open position, and a pair of suction valveseach constructed to connect the cylinder on one side of the piston witha source of suction when in open position, hollow piston rods extending.from said piston in opposite directions, each having a slidingengagement in the bearing aperture of one of said cylinder heads, meansfor admitting atmospheric airthrough each of said hollow piston rods toone of said air inlet valves, and a longitudinally movable valveactuating sleeve extending through at least one of said hollow istonrods 0 eratively connected with said suction an air valve, andwith-means for connecting the cylinder with a source of suctionunder thecontrol of said suction valve, means for connecting one of said hollowpiston rods with a part to be operated, the other of said hollow pistpnrods being constructed to be withdrawn within its bearing aperture inthe adjacent cylinder head, when the piston isin oil position, a collaron the valve actuat ng, sleeve for closing said bearing apertu're whenthe parts are in off position,

' and means for connecting'said valve actuating sleeve with an operatoroperated part. 4. A power actuator comprising among its mem ers acylinder having its opposite ends closed by heads provided with bearingapertures,=a double acting piston in said cylk inder, reversing valvemechanlsm, including normally closed air'inlet valves each con structedto admit air on one side of the pistonwhen in open position, and a pairof suction valves each constructed to connect the cylinder on one sideof the piston with a source of sliction when in open position, hollowpiston rods extending from said pis- .ton' in opposite directions, eachhaving a I sliding engagement in the bearing aperture of one, of saidcylinder heads, means for admittln'g atmospheric air through said hollowpiston'rods to one 01 saidair inlet valves, and a longitudinally movablevalve actuating sleeve extending through at leastone of said hollowpiston rods operatively connected with said suction and air valve, andwith means for connecting the 'cylinderwith a source of suction underthecontrol of said suction valve, means for connecting one of said hollowpiston rods with -a part to be operated, the othe1;hollow piston rodbeing constructed to be withdrawn within its bearing aperture in theadjacent cylinder head when the parts are in oflf position, a collar .onthe valve actuating sleeve vfor engaging the adjacent cylinder head andclosing said bearing aperture therein, said collar being constructed andarranged to limit the return movement of said sleeve and holdbothsuction valves in op )ositely disposed air inlet and suctionva vesin each of said valvechambers, two hollow piston rods connected withsaid piston,'each extcndingthrough the bearing aperture of one of thecylinder heads, one of said piston rods being provided with means forsupplying atmospheric air to one of said valve chambers, and with meansfor attaching it to a part to be operated, the other of said piston rodsbeing provided at its outer end with a guiding aperture and with airinlet apertures 'for supplying air to the other of said valve chambers,and being constructed to be withdrawn within its bearing aperture in theadjacent c linder head when the piston is in ofl' pos tion', a hollowvalve actuating sleeve extending through the said bearing aperture inthe outer end of said hollow piston rod and being operatively connectedwith said air inlet and suction valve, said sleeve being provided withmeans for connecting said suction chamber to asource of suction, andwith means for connecting said sleeve with an operator operated part,and a collar on said sleeve for,closing the bearing aperturein theadjacent cylinder head when the parts are in oil position. v

i 6. A power actuator comprising among its members a c linder closed ateach ,end'by a head provi ed with a "bearing aperture therein, a doubleactingpiston in the cylinder having its central portion provided each of-with two valve chambers each communicating with the c linder. on oneside of the piston only, an a centrallyflocate'd suction chamber,reversing valve mechanism including oppositely disposed air inletandsuction valves in each of said valve chambers, two hollow piston rodsconnected with said piston; each extending through the bearing apertureof one of the cylinder, heads, one of said piston rods being providedwith means for supplying atmospheric air to one i of said ,valvechambers, and with means for attaching it toa part to be operated, theother of said piston rods being provided at its outer end with a guidingaperture and With air inlet apertures for supplying air to the otherofsaid valve chambers, and being constructed to be withdrawn withln itsbearing aperture in the adjacent cylinder head when the piston is in 0dposition, a hollow valve actuating sleeve extending through said bearingaperture in the outer end of said hollow piston rod, operativelyconnected with said inlet and suction valves, and provided with meansfor connecting said suction chamber with a source of suction,

I and means for connecting said sleeve with an operator operated part,retracting means for said sleeve, and a stop collar on said sleeveadapted to engage the adjacent cylinder der, reversing valve mechanism,including normally. closed air inletvalves each constructed to admit airon one side of the piston when in open position, and a pair of suctionvalves each constructed to connect the cylinder onone side of the pistonwith a source of suction when in open position, 5 piston rods extendingfrom said piston in opposite directions, each having a slidingengagement in the bearing aperture of one of said cylinder heads, meansfor admitting atmospheric air to one of said air inlet valves, 40 and alongitudinally movable Valve actuating member operatively connected withsaid suction and air valve, and with means for connecting the cylinderwith a source of suction under the control. of said suction valve, meansfor connectin one of said piston rods with. a part to e operated, theother of said piston rods being constructed to be withdrawn within itsbearing aperture in the adjacent cylinder head, when the piston is inofi position, a collar on the valve actuating member for closing saidbearing aperture when the parts are in ofi position, and means forconnecting said valve actuat ing member with an operator operated part.

In testimony whereof we afiix our signatures.

CALEB S". BRAGG. VICTOR W. KLIESRATH.

